Hydraulically-actuated device



May 22, 192s. 1,670,786

P. W. SEEWER HYDRAULICALLY ACTUATED DEVICE Filed Aug. l2, 1924 Figi.

@fly/@MLM Patented May 22, 1928.

UNITED l .STATES increase eArE-N'r fornace.

PAUL WERNER sEEwER, OE LONDON,ENeLA1\;r;o,l AssrGNoa TO'TEE ENGLISHELEQ- TRIO COMPANY LIMITED, OE LONDON, ENGLAND, A BRITISH COMPANY.

HYDEAULIoALLYeACTUATED DEVICE.

Application ined August 12, 1924, serial No. 731,654, and in creat Britain December-22, 1923.

This invention relates to the control of hydraulically actuated devices and provides for the carrying out of this control by means of a regulating valve inuen'cingthe fiovv` of pressure fluid7 the effect of which valve is varied progressively as the moving partof the device proceeds on its course. Control 'of this kind is desirable in cases where it is advantageousv for the movement of the controlled part to be'much more rapid at one stage of its movement than at another; for instance, in the case' of the main valve for the supply to an hydraulic turbine the closing movement should be relatively rapid in the early and middle stages and should gradually be retarde-d as the completion of the closure is approached. Conversely, dur'- ing the opening the movement should be slow at first and then morerapid. i l

In hydraulically actuated devices yto lwhich the present invention relates there is employed a servo-motor in the form of a cylinder closed atboth ends and having a piston working in it and passages or conducting pressure fluid into and exhausting itfrom the space within the cylinder on each side of the piston. A regulating valve is' inserted in one of these passages being ,so arranged that the whole movement ofpressure fluid into and out of the cylinder space with -which `it connects takes place through this Valve. The valve comprises an adjustable regulating member and this member inaccordance with the invention isl operatively connected with the actuated part which vitself is in operative connection with the piston of the servo-motor. The movement of the regulating member of the valve which takes place by reason of its operative connection with the actua-ted part effects rthe variation of the throttling effect of the regulating valve on the Apressure fluid' passing through it and thereby determines the speed at which the servo-motor moves. lith this arrangement it is possible to obtain very great variation inspeed of the actuated part at different points in its stroke.

The invention will now be described by way of example with reference to the accompanying drawings, Figure 1` of which shows in section a part of a main valve for controlling the supply of fluid to an hydraulic turbine together with a regulating valve having an adjusting menthe? the vFigure o lform ol"A a screw threaded spindle adapted gradually to retard the closing movement .of -the mam valve according to the invention.

Figure-'2 is an enlarged sectional view of the regulating valve portion of Figure -1 and p shows an enlarged detail view of the screw threaded spindle.

The outer circular wall of the valve is dei noted by 1 and a two part central member by ,2, each` part being Afixed by ribs to the outer parts of the valve. The ribs attached to the right hand pai-tarel denoted by 3 and are fixed to the tubular member 6. Water fiows through the yvalve from left to right in Figure 1 and when it reaches the central member 2 rit flows through the annular passage 4 formed by the members 1 and 2. The

`movable part of the valve bywhic'h the flow of fluid isA regulated is the annular body 5 which is adapted to slidev axially along the tubular member 6. The right hand extremity of the annularv body 5 is thickened'up 'and is provided with'l hydraulic Washers so as to act as a double acting piston .11 with- 1n an annular cylinder having lspaces 7 and 8 for the' operating fluid.l VVhenspace 7 is connected to a sourcejot' fiuidundery pressure and space 8 1s connected to exhaust, the

vannular body 5 movestothe left andthe closingaction commences and is v'completed as soon as the end 9 ot'the body 5 reaches the ring 10 upon ythecentral. member 2. In

a converse manner opening is effected by connecting the space 7 to exhaust and kthe space 8 to the source of pressure;

The adjusting member of' vthe main' valve is a spindle 12 having on apart of its surface a screw thread 1,8 preferably of squaresecr tion which works within cylinder 14C of' such size'that the top of threads 13 hasjust suficient clearancetherein to permit free move- .ment without producing appreciable leakage By varvingxthe Ythreaded length of spindle which` lies in the cylinder the resistance to the passage of the fluid through the cylinder'is adjusted. The cylinder 14' will, in general, form part of, a `chamber within which the whole of the spindle is housed, and it'will have apertures for the inflow and outflow of fluid at the two ends oftheportion which is intended to include that part of the spindle which is eective for vregulating action. In thiscase cylinder 14 is arranged with one end discharging directly Cil into space 7. A reduced .portion of spindle 12 extends through part of cylinder 14 and projecting therefrom is attached in suitable manner to the piston 11 of the annular body 5 so las to move therewith, bringing more or less of the threaded portion into the path of the pressure fluid as the movement of the piston 11 proceeds.

In the present instance cylinder 14 is lscrewed into the end flange 15 of the main `valve and its outer end is closedv by cap 16 which screws onto the end ot' the cylinder and forms a housing for spindle 12.

ASpindle 12 is reduced or is joined to a part of `smaller cross section at its end adjacent to space 7 sothat only a small .length of its threaded portion rests within cylinder 111 when the annular body 5 is in its open position, .as shown in the drawing. The pressure fluid enters cylinder' 14 near its outer "end, by way of duct 17.

- the spindle 12 of varying vdepth Aor Width.

Gil

Another kind of variation may be obtained by varying the pitch of the thread 13, so that there is a varying number of threads Vper inch along the length of the threaded spindle. All these variations are clearly shown in the large view of the spindle in 'Figure 3. In `this `figure the depth of the thread is a maximum at its extreme left handL where a minimum amount of throttling oi the fluid is required. The depth vgradually decreases until it isa minimum at the extreme right hand. It will alsobe observed that both the pitch land the width of the space of the thread are greater at the left hand than at the right hand. The thread can either be cut directly upon the spindle or a number of collars, upon the outside of each of which some of the thread has been cut, may be slid upon the spindle and held in position by an end bolt.

Another type kof change in the formof the controlling action may be brought about by arranging that the regulating part of the spindle is not in action during the whole of the movement. This could beprovided for in the drawings by removing thread 13 for a `certain distance on the left side of the threaded part of spindle 12 (for examplel up to the dotted line 19 in Figure 3) so that the water can flow freely througlrthe `duct 17 into the chamber 7 until the body 5 has advanced adeiinite distance suflicient to bring the threaded part into the cylinder 14. The point in the stroke of the body 5 at which this takes place may be made adjustable by an arrangement :for producingrelative` displacement of the threaded part of the spindle and the cylinder in addition to the displacement which occurs when thedevice is in action,

Vhen it is desired to open the main Valve the pressure fluid is supplied to the duct 18 `in Figure 1 and the duct 17 is-connected to exhaust. The annular body 5 will then commence to move very slowly towards the open direction since the water can only escape to exhaust very slowly through the many threads which now lie `in t-he cylinder 14 between the duct 17 and the space 7. As the o ening movement continues and fewer threacs are effective it willbecome more and more rapid. y

It will `be recognized that other construcltional ymodifications are possible `one Lof which is to have the thread upon the inside of the cylinder 14; and to arrange that it co-acts With an unthreaded spindle of suitable diameters. Moreover thel relative movement betwen the spindle and the cylinder could be provided by displacement of the latter instead of the former.

l/Vhat I claim as my invention and desire to secure by Letters Patent is :-l e

1. Hydraulic actuating means by which the speed of movement-of the actuated part is made dependent upon its position c omprising, .in combination with the actuated parts, a servo-motor operatively connected therewith and being in the form of. a lcylinder closed at both ends and having a piston working therein and passages `for conductving` pressurel fluid intov and exhausting it from the space on each side of the piston, afregulating valve insert-edin one of said passages so rthat the whole movement of pressure fluid into and out of one of said spaces which accompanies thevmovement of 1 the piston takes place through the saidvalve, a movable regulating member in the said valve, means operatively Aconnecting Vthe said regulating member with the actuated part so that they move simultaneously and. means adjusted by the said regulating member'ifor varying the throttling effect of the said regulatingk valve on the pressure fluid passing through it. l p

2. Hydraulic Lactuating means by vWhich the speed of' movement of the actuated part is made dependent upon its position comprising, in combination with the actuated l part, a servo-motor operatively connected therewith and being in the form of a cylinder closed at both ends an'dhaving a piston working therein and passages for conducting pressure fluid into and exhausting it from the space on each'side of the piston, au

regulating valve inserted in one of said passages so that the whole movement of presu sure fluid into and out of one of said spaces which accompanies the movement of the piston takes place through the said valve, a movable regulating member in the said i-,eijopee valve, means operatively connecting the said regulating member withl the actuated Apart so that theyr movesimultaneously andmeans adjusted by the said regulating member for varying the length of a restricted'passage for the pressure fluid through the said regulat-ing valve. y

l3. Hydraulic actuating means by which the speed of moveinentof' the actuated part is iii-ade dependent upon-'its positionv comprising, in combination with'the actuated part, a scrvofmotor voperati'vcly connected therewith and being in the form oit a Cylinder closed at both ends and having a pistonivorliing therein and passages for conducting pressure fluid into and exhausting it from the space on each side of the piston,

a regulating valve inserted in one of said passages so that the whole movement pressure fluid into and out of one of said spaces which accompanies the movement of the piston takes place through the said valve, a movable regulating member in thesaid valve, means operatively connecting the said regulating member with the actuated part so that they move simultaneously and means adjusted by the said regulating memberfor varying simultaneously the length and the cross section ot a i'esti'ictedpassage for the pressure fluid through the said regulating valve.

t. Hydraulic actuating means by which the speed or" movementoi the actuated part is made dependent upon its position comprising, in combination with the actuated part, a servo-motor operatively connected therewith and being in the orm of a cylinder closed at both ends and having a piston working therein and passages for conducting pressure fluid into and exhausting it from the space on each side of the piston,

a regulating valve inserted in one of said passages so that the whole movement of pressure fluid into and out of one of said spaces which accompanies the movement of the piston takes place through the said f'alve, a movable regulating member in the said valve, means operatively connecting the said regulating member with the actuated part so that they rmove simultaneously and means adjusted by the said regulating member for varying rthe length of a restricted passage formed by means of a screw thread for the pressure fluid through the said regulat-ing valve. l l

5. The combination. in a valve of a passage for fluid, a movable valve member adapted to open and close said passage, a pressuretight chamber external to said passage, a piston working in said chamber and operatively connected with said closing member, fluid-conducting means restricting the flow of pressure fluid at any instant to asingle direction relative to the space between the said piston and' one end of said chamber, a

ythe-said regulating valve so that this length increases; as the'piston'moves in its chamber towards the position invvhich it closing' of the 4main valve. t E'6. ",lhecon'ibination in a valve of a passage for fiui'd, a? movable valve member adapted to open and close said passage, a pressuretight chamber external to said passage, a piston working inv said chamber and operatively 'connected with said closing member, fluid-conducting means restricting the flow of pressure fluid at any instantto a single direction relative to the space between the said piston and one end of said chamber,`a regulating valve .embodied in said conducting means so that the whole movement of pressure fluid into and out of the said space associated vwith the movement of the said piston takes place through the said regulating valve, a movable member in said regulating valve operatively connected with the said piston andcffecting the adjust-ment of the length of a restricted passage, formedby means ota screw thread, through the said regulatingvalve so that the active length of the screw thread increases as the piston moves in its chamber towards the position` in which it produces the closing of the main valve.

7. The combination in a valve of a passage forfluid, a pressure-tight chamber, a member working in said chamber and extending by way of a pressure-tight aperture to the outside of said chamber and into said pas-` sage, the said member having itsend Within i l ilo the chamber enlargedto form a piston and having that part of it which extends outside the chamber adapted to serve as a closing member for the passage, fluid conducting means restricting the flow. of pressure fluid at any instant to a single direction relative to the space between the said pistonand one end oi. said chamber, a regulating valve embodied in said conducting means so that the whole movement of pressure fluidinto and vout of the said space associated with the movement of the said piston takes place through the Said regulating valve, a movable member in said regulating valve operatively connected with the said piston and effect-ing the adjustment of the length of a restricted passage through the said regulating valve so that this length increases as the piston moves 4in its chamber towards the position in Which it produces the closing of the main valve.

8. The combination in a valve of a passage produces the e for fluid, a pressure-tight chamber,n a inember Workin'gin said Chamber and extending by Way of Aa pressure-tight aperture to the outside 'of said elifanb'er and into said passage, the said member 'having its 'end Within the chamber enlarged to forni a pistonr and having that ypart or' trvvh'ioh extends "outside the :chamber adapted lto serve as a. closing member for the passage, fluid conducting means restricting vthe flow of pressure Huid at any instant to a single l'direction relative to the space between the said 'piston and one end of said chamber, a regulating v,valve ernboded in said conducting means sothat the Whole `rnovement of pressure fluid into and out of the 'said 'space associated With `the movement of the said vpistoia takes plate through the said regulating valve, a movable member 'in said regulating valve opera'- tively connected with the said lpiston and effecting the adjustment ofthe length of a restricted passage, formed by Imeans 'of a 'screw thread, through the said regulating valve so that the active length of the serevv thread increases as 'the ypiston Ymoves in its chamber tovvar'ds the position in which it produces the closing of the main valve.

In testimony "whereof I afxmy signature.

PAUL WERNER snEWnn. 

